Parametric decomposition of optic flow by humans

Ego motion and natural motions in the world generate complex optic flows in the retina. These optic flows, if produced by rigid surface patches, can be decomposed into four components, including rotation and expansion. We showed previously that humans can precisely estimate parameters of these components, such as the angular velocity of a rotational motion and the rate of expansion of a radial motion. However, natural optic flows mostly display motions containing a combination of more than one of these components. Here, we report that when a pure motion (e.g., rotation) is combined with its orthogonal component (e.g., expansion), no bias is found in the estimate of the component parameters. This suggests that the visual system can decompose complex motions. However, this decomposition is such that the presence of the orthogonal component increases the discrimination threshold for the original component. We propose a model for how the brain decomposes the optic flow into its elementary components. The model accounts for how errors in the estimate of local-velocity vectors affect the decomposition, producing the increase of discrimination thresholds.

[1]  D. Burr,et al.  Two stages of visual processing for radial and circular motion , 1995, Nature.

[2]  A Johnston,et al.  Concurrent measurement of perceived speed and speed discrimination threshold using the method of single stimuli , 1999, Vision Research.

[3]  J. Koenderink,et al.  Detection of divergence in optical flow fields , 1996 .

[4]  G. Orban,et al.  Human velocity and direction discrimination measured with random dot patterns , 1988, Vision Research.

[5]  T. Freeman,et al.  Human sensitivity to expanding and rotating motion: effects of complementary masking and directional structure , 1992, Vision Research.

[6]  J A Perrone,et al.  Model for the computation of self-motion in biological systems. , 1992, Journal of the Optical Society of America. A, Optics and image science.

[7]  G. Orban,et al.  Responses of macaque STS neurons to optic flow components: a comparison of areas MT and MST. , 1994, Journal of neurophysiology.

[8]  Simon K. Rushton,et al.  Optic Flow and Beyond , 2004 .

[9]  D Regan,et al.  Visual responses to vorticity and the neural analysis of optic flow. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[10]  K. Tanaka,et al.  Analysis of motion of the visual field by direction, expansion/contraction, and rotation cells clustered in the dorsal part of the medial superior temporal area of the macaque monkey. , 1989, Journal of neurophysiology.

[11]  S. Watamaniuk.  High-Level Motion Processing: Computational, Neurobiological, and Psychophysical Perspectives , 1999 .

[12]  A. Verri,et al.  First-order analysis of optical flow in monkey brain. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[13]  M G Harris,et al.  Independent Detectors for Expansion and Rotation, and for Orthogonal Components of Deformation , 2001, Perception.

[14]  K. Tanaka,et al.  Underlying mechanisms of the response specificity of expansion/contraction and rotation cells in the dorsal part of the medial superior temporal area of the macaque monkey. , 1989, Journal of neurophysiology.

[15]  Jose F. Barraza,et al.  Parametric measurements of optic flow by humans , 2004 .

[16]  M. Longair.  The Theoretical Framework , 1998 .

[17]  R. Wurtz,et al.  Sensitivity of MST neurons to optic flow stimuli. I. A continuum of response selectivity to large-field stimuli. , 1991, Journal of neurophysiology.

[18]  A. Yuille,et al.  A Theoretical Framework for Visual Motion , 1996 .

[19]  Jan J. Koenderink,et al.  Detection of first-order structure in optic flow fields , 1996, Vision Research.

[20]  Jan J. Koenderink,et al.  Local structure of movement parallax of the plane , 1976 .

[21]  Dennis M. Levi,et al.  “Weber's law” for position: the role of spatial frequency and contrast , 1992, Vision Research.

[22]  Robert J. Snowden,et al.  The Effects of Adapting to Complex Motions: Position Invariance and Tuning to Spiral Motions , 1996, Journal of Cognitive Neuroscience.

[23]  S P McKee,et al.  Motion interference in speed discrimination. , 1989, Journal of the Optical Society of America. A, Optics and image science.

[24]  R. Wurtz,et al.  Sensitivity of MST neurons to optic flow stimuli. II. Mechanisms of response selectivity revealed by small-field stimuli. , 1991, Journal of neurophysiology.

[25]  Norberto M. Grzywacz,et al.  Measurement of rate of expansion in the perception of radial motion , 2005, Vision Research.

[26]  J J Koenderink,et al.  Detection of vorticity in optical flow fields. , 1994, Journal of the Optical Society of America. A, Optics, image science, and vision.

[27]  M. Graziano,et al.  Tuning of MST neurons to spiral motions , 1994, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[28]  D C Van Essen,et al.  Functional properties of neurons in middle temporal visual area of the macaque monkey. I. Selectivity for stimulus direction, speed, and orientation. , 1983, Journal of neurophysiology.

[29]  D. Regan,et al.  Looming detectors in the human visual pathway , 1978, Vision Research.

[30]  G. Westheimer,et al.  Discrimination of direction of motion in human vision. , 1994, Journal of neurophysiology.

[31]  Norberto M Grzywacz,et al.  Measurement of angular velocity in the perception of rotation , 2002, Vision Research.

[32]  Takeo Watanabe,et al.  High-Level Motion Processing , 1998 .

[33]  Gerald Westheimer,et al.  Discrimination of short time intervals by the human observer , 1999, Experimental Brain Research.

[34]  Norberto M Grzywacz,et al.  Local computation of angular velocity in rotational visual motion. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[35]  John H. R. Maunsell,et al.  Functional properties of neurons in middle temporal visual area of the macaque monkey. II. Binocular interactions and sensitivity to binocular disparity. , 1983, Journal of neurophysiology.

[36]  S. McKee.  A local mechanism for differential velocity detection , 1981, Vision Research.

[37]  R. Hetherington.  The Perception of the Visual World , 1952 .

[38]  Constance S. Royden,et al.  Mathematical analysis of motion-opponent mechanisms used in the determination of heading and depth. , 1997, Journal of the Optical Society of America. A, Optics, image science, and vision.